How to burn a project, soup to nuts....

Well, I wanted to burn my first project board, SMTCylon.  How did I do it.  This is the step by step of how it was done.

First, I was luck that Dale Wheat, creator of tinyCylon had posted his code and schematics in the public domain.  All I needed to do do was build his circuit and work out the details:

Ok, now that I had a working model, just draw out the circuit as a surface mount version...

On, transparancy of course... Nicely squished between glass and the photo board.  Here right before I removed the white protective film.

Then transfer that to a photo senstative board...  Here a fresh CF (Compact Flourescent) Bulb, 15w, was placed 8" above the board for 8 minutes.  Moving the board around seemed to help distributed the energy evenly over the board.  Failure to do so left unexposed areas.

Next, develop the image in developer.  Note: Developer must be EXACTLY 100 - 110 degrees.  I've found best luck at 105 degrees F exactly.  I nuke it up in the microwave and let it cool to 105.  Measure with a thermometer and be sure...  Do NOT expose to white light as I was doing here or you may lose the image.  Depends on the frequency of the white light.  I watched 5 boards melt til I realized what was happening.

After a few seconds the image should appear.  DO NOT EXPOSE TO WHITE LIGHT. If the image does not appear and the board stays dark green, your developer is bad or or was too cold.  The board is destroyed.  (It could be reused if wiped, resurfaced, etc)  If the board has an image, gently wipe with a sponge as there may be residue, this helps to dislodge it.  Run the board under cold water to set the image.  You may now turn on the lights.

You can now heat up your etchant.  Again, I've been doing this in the microwave.  I started with Ferric Oxide, but have since switched to Muratic-Oxide.  It's a lot less messy, but equally as dangerous.  (1 part muratic acid added to 2 parts hyrdrogen peroxide.  Read that carefully.  Always add acid.  Add acide to peroxide, not the other way around.)  I get the etchant to about 150f and drop in the board.  Pictured below is Ferric Oxide which stains nasty nasty!

Moving the board through the etchant seems to accelerate the process.  In about an hour the board will be fully etched.  In this case, the board was not fully exposed and there were some areas that would not full etch.

After the board is washed and dried it can typically be cut with a pair of tin sheers.

In my case, I was experimenting with a new circuit, so I test soldered the majority of the new board.

All that was missing was the CPU.  As part of the design of the SMTBoards web site, I had decided that all CPUs from this site would come preprogrammed, and therefore I would not design in circuit programming into my boards.  Ok, it's kinda cheating, but it does simplify the design.

But that also means inventing some new technology; An out of circuit programmer for an SMT chip.  That's where the Tiny13ISP comes in.  Here's the first of its kind, cut from the same board as the SMTCylon prototype:

And here's the first time a Tiny13 every phoned home on one of these:

All that was left to do was upload the program, solder in the chip, and see if it worked....

Turns out after talking to Dale a bit, I was a bit off on the timing.  But that's another story....